狭卵链格孢菌毒素细交链孢菌酮酸诱导稗草叶片氧化胁迫和抗氧化酶变化的研究

目的]确定细交链孢菌酮酸（tenuazonic acid,TeA）对稗草的毒害作用是否与其诱导氧化胁迫及抗氧化酶活性变化有关。方法]通过离体试验研究了TeA处理稗草叶片丙二醛和过氧化氢含量及抗氧化酶活性的变化。结果]稗草叶片经500μmol/L TeA处理后,叶片中丙二醛和过氧化氢含量分别较对照增加了247.86%和67.00%,表明TeA处理诱导了稗草叶片中活性氧暴发,并导致丙二醛和过氧化氢的大量积累。TeA引起超氧化物歧化酶（SOD）、谷胱甘肽还原酶（GR）和过氧化氢酶（CAT）活性显著升高,其中在500μmol/LTeA处理下,稗草叶片SOD、GR和CAT活性均较对照增加1倍以上。结论]TeA诱导活性氧的产生引起稗草叶片氧化胁迫,同时诱导叶片抗氧化酶活性升高。

Research on Oxidative Stress Induced by Tenuazonic Acid from Alternaria augustiovoide and Changes in Antioxidant Enzyme Activities in Leaves of Echinochloa crusgalli

Objective] The aim of the study was to determine whether phytotoxicity of TeA against Echinochloa crusgalli leaves was correlated with oxidative stress caused by generation of reactive oxygen and the changes of antioxidant enzymes activity.Method] The changes of malondialdehyde(MDA) content,hydrogen peroxide(H2O2),and activities of superoxide dismutase(SOD),glutathione reductase(GR) and catalase(CAT) were studied by leaf segment method in vitro.Result] After the treatment of 500 μmol/L TeA,the content of MDA and H2O2 increased by 247.86% and 67.00%,respectively,indicating that the accumulation of MDA and H2O2 in E.crusgalli leaves was due to the reactive oxygen burst induced by TeA.TeA induced a significant increase in activities of SOD,GR and CAT.At 500 μmol/L TeA,activities of SOD,GR and CAT increased more than one fold compared with the control.Conclusion] TeA could not only cause oxidative stress in leaves of E.crusgalli through the induction of reactive oxygen,but also induce the increasing of antioxidant enzyme activity.